Place a medium skillet over medium heat and add the butter and canola oil. Once the butter has melted add all the mushrooms and shallot and stir to coat with the fat. Cook, stirring occasionally for 12-15 minutes or until the mushrooms are brown and beginning to caramelize.
Stir in the Dijon mustard and allspice and cook for 30 seconds. Pour in the beef broth and bring to a simmer and cook for two minutes.
Mix together the cornstarch and water and stir into the simmering mushrooms. Simmer for another minute or until the gravy has thickened.
On toasted sourdough topped with shaved parmesan and parsley.